Influence of a 5HT1 receptor agonist on gastric accommodation and initial transpyloric flow in healthy subjects

Sumatriptan, a 5HT1 receptor agonist, inhibits antral motor activity, delay s gastric emptying and relaxes the gastric fundus. The aim of this study wa s to characterize the effect of sumatriptan on transpyloric flow and gastri c accommodation during and immediately after ingestion of a liquid meal usi ng duplex sonography. Ten healthy subjects were investigated twice on separ ate days. in random order either sumatriptan 6 mg (Imigran(R) 0.5 mt) or a placebo were given s.c. 15 min before ingesting 500 mt of a meat soup. The subjects were examined during the 3-min period before ingestion of the liqu id meal, the 3-min spent drinking the meal and 10 min postprandially. Sumat riptan caused a significant widening of both the gastric antrum (P = 0.02) and the proximal stomach (P = 0.01) 10 min postprandially as compared with placebo. It caused no significant differences in time to initial gastric em ptying (P = 0.2), but significantly delayed commencement of peristaltic-rel ated transpyloric pow (P = 0.04). Sumatriptan had no significant effect on mean abdominal symptom scores, but after sumatriptan there was a significan t negative correlation between width of postprandial antral area and postpr andial nausea and between width of postprandial antral area and postprandia l bloating. We therefore conclude that sumatriptan causes a postprandial di latation of both the distal and the proximal stomach with no change in dysp eptic symptoms nor in length of time to first gastric emptying. Time to com mencement of peristaltic-related emptying is delayed.